Disease Unit

Question 1

Virus

Answer 1

An infectious agent that kills host cells and can result in tissue damage, organ failure and death. It weakens the immune system so other pathogens infect the host. It can’t replicate without a host organism. Examples include: HIV, influenza and herpes

Question 2

Bacteria

Answer 2

Secretes toxins that harm or kill the host. It replicates independently from the host organism and can replicate inside or outside the host cell. Examples include: Tuberculosis, tetanus and cholera

Question 3

Fungi

Answer 3

Secrete enzymes that digest skin, nails and hair. They can lead to respiratory infection people with weakened immune systems and they can secrete toxins that harm the host. Bacteria replicate independently from the host. Examples include: ringworm, meningitis and pneumonia.

Question 4

Parasite

Answer 4

Damages the host cells, tissue and organisms. They block the movement of materials inside the body and remove vitamins and minerals from food before the host can absorb them. It replicates independently from the host cell and can replicate within or outside of it. Examples include: malaria, parasitic worms and toxoplasmosis.

Question 5

Protist

Answer 5

Damage the host cells causing illness, symptoms of the infection often kill the host. It replicates independently of the host organism. Examples: Giardiasis, cyclosporiasis and malaria.

Question 6

Prion

Answer 6

A type of protein that can trigger normal proteins in the brain to fold abnormally. It replicates in the host. Examples: Mad cow disease, creutzfeldt-jakob disease and scrapie

Question 7

Cleanliness

Answer 7

Hygienic stuff like washing and dry hands, covering your mouth and nose with a tissue when sneezing or coughing. Food hygiene like cleaning surfaces, chopping boards, utensils, pots, pans, dishes and storage containers.

Question 8

Sanitation

Answer 8

Cleaning surfaces like kitchens and bathrooms properly to stop the spread of diseases.

Question 9

Social distancing

Answer 9

Preventing the spread of a contagious disease by maintaining a physical distance between people and reducing the number of times people come into close contact with each other.

Question 10

Isolation/Quarantine

Answer 10

Keeps people with the disease away from their community and the rest of the population. It is effective in preventing the spread of the disease because it removes the carrier from the population preventing interactions with others.

Question 11

Immunisation

Answer 11

Allows immunity to develop without exposure to the disease itself. It stimulates your body’s immune system to produce antibodies which fight and kill the virus. If you come into contact with this virus again, your body will be prepared to fight it.

Question 12

Antibiotics

Answer 12

Chemicals that work by killing or reducing the growth of bacteria. It is effective in blocking processes in bacteria, killing the bacteria or stopping them from multiplying. This helps the body’s natural immune system to fight the bacterial infection. Examples include: penicillin and amoxicillin

Question 13

Antiseptics

Answer 13

A group of chemicals that kill microbes on the outside of the body. It is effective in stopping the growth of microorganisms on the skin. They’re used daily in medical settings to reduce the risk of infection and stop the spread of germs. Examples include: hydrogen peroxide and antibacterial dye

Question 14

Disinfectants

Answer 14

Group of chemicals that kill microbes on surfaces, floors and toilets. They’re important to use because disease and bacteria can live on surfaces.

Question 15

Second line of defence - Innate immunity

Answer 15

The main purpose of this systems response is to immediately prevent the spread and movement of foreign pathogens throughout the body.

Question 16

Third line of defence - The adaptive system

Answer 16

This system has a memory that allows it to better defend the animal from pathogens it has encountered before. It is also very specific, has a slow response time, develops throughout an animal’s lifetime and has specific responses to certain pathogens.

Question 17

Physical Barriers - Skin

Answer 17

The outer layers of skin contain keratin, and microorganisms cannot penetrate it unless it is broken. It has its own population of normally harmless bacteria. Their presence helps keep invading pathogens from multiplying. If the skin is broken, the blood-clotting mechanism very quickly forms a seal across the wound to prevent the entry of pathogens.

Question 18

Examples of Physical Barriers

Answer 18

The mucous membranes produce mucus that trap microbes. Hair within the nose filters air containing microbes, dust, pollutants. Cilia lines the upper respiratory tract traps and propels inhaled debris to throat. Urine flushes microbes out of the urethra

Question 19

Second line of defence - Non Specific Responses

Answer 19

Inflammation response - A response to when tissue is damaged, such as by the invasion of a pathogen. The area becomes red, hot, swollen and painful, this is due to the blood circulation to the area being increased. This helps confine the pathogen while an increased number of white blood cells destroy the pathogen

Question 20

Second line of defence - Phagocytosis

Answer 20

White blood cells that actively move from the blood to tissues where they ingest and destroy any foreign material including pathogens

Question 21

B Cells

Answer 21

White blood cells from the bone marrow that when activated create antibodies against invading bacteria and viruses.

Question 22

T Cells

Answer 22

White blood cells from the thymus that when activated produce substances that attack infected host cells.

Question 23

Memory Cells

Answer 23

These cells are able to recognize antigens which enter the body a 2nd time. They can provide instant defence so the antigen can be eliminated quickly, sometimes before any symptoms.

Question 24

Third line of defence - Active immunity

Answer 24

The immunity to a pathogen that occurs following exposure to said pathogen. When the body is exposed to a disease, B cells create antibodies that assist in destroying or neutralizing the disease agent.

Question 25

Passive Immunity

Answer 25

This is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system. A newborn baby acquires passive immunity from its mother through the placenta.

Question 26

The difference between antigens and antibodies and how they interact to form immunity to disease.

Answer 26

Antigens are molecules capable of stimulating an immune response. Antibodies are Y-shaped proteins produced by B cells of the immune system in response to exposure to antigens. Antibodies bind to the antigens to help eliminate the pathogen.

Question 27

Antibodies

Answer 27

Y-shaped proteins made by your immune system’s B lymphocytes or B cells. B cells attack and eliminate viruses and other toxins outside the cell. They do this by making specific antibodies for a single type of antigen. These lock on to their specific antigens and tag them for attack. They also block these antigens, keeping them away from your healthy cells. Their purpose is to kill antigens, stopping infection.

Question 28

Third line of defence - Acquired immunity

Answer 28

Immunity that the body develops after it overcomes a disease, or through immunization

Question 29

What is a disease?

Answer 29

A condition with specific symptoms that reduces health by altering how an organism functions.

Question 30

What is an infectious disease?

Answer 30

A contagious illness caused by pathogens transmitted between hosts. Examples include; measles, chicken pox or the flu.

Question 31

What is a non-infectious disease?

Answer 31

An illness caused by lifestyle, genetics and environmental factors. It is not contagious. Examples include; cancer, cardiovascular disease and diabetes.

Question 32

What do pathogens seek?

Answer 32

They seek to reproduce and spread to new hosts. They’re an infectious agent that causes diseases or illness in an organism.

Question 33

What are examples of direct transmission?

Answer 33

Skin to skin (direct transmission through close physical contact), droplets (direct transmission through mucus that comes from the nose or mouth) and body fluids (direct transmission through the exchange of fluids like blood).

Question 34

Examples of droplet transmission

Answer 34

Sneezing directly on to another person, and drops of mucus coming into contact with their mucous membrane

Question 35

Examples of body fluid transmission

Answer 35

Touching the blood of another person when you have an open wound on your hand or coming into contact with body fluids during sexual contact

Question 36

Examples of skin to skin transmission

Answer 36

Touching the fluids released when someone scratches or bursts blisters on their skin.

Question 37

Branches of immune system

Answer 37

There are two branches of the immune system: the innate and the adaptive immune system. The innate immune system is rapid, but non-specific in its response, whereas the adaptive immune system is slower, but specific. The two systems work together. Almost all white blood cells belong to the innate immune system. The two cells that belong to the adaptive immune system are B and T cells.

Question 38

How Does Your Immune System Recognize Harmful Agents?

Answer 38

Harmful agents are recognized through antigens, which are any substance that elicits an immune response. The adaptive immune system utilizes MHC molecules to identify the presence of a harmful agent. They can kill the infected cell, neutralize the harmful agent, or recruit more immune cells. The innate immune system utilizes PRRs such as the Toll-like receptors to identify structural components of the harmful agent.

Question 39

Barrier defences

Answer 39

A part of the body’s most basic defence mechanisms. It is not a response to infections, but are continuously working to protect against a broad range of pathogens. Examples include: skin, mucous membranes, tears, earwax, mucus, and stomach acid.

Question 40

First line of defence - Chemical Barriers

Answer 40

Mucus - Within the body’s digestive, respiratory, reproductive and urinary tracts our bodies produce a thick slimy mucus that acts as a method of preventing the physical entry of pathogens. Tears -Contain a chemical that inhibits bacterial growth. Stomach acid - due to the stomach’s highly acidic nature it kills pathogens. There are populations of harmless microorganisms in the vagina. They act on cells shed from the walls of the vagina to create acid conditions which inhibit the growth of some bacteria and fungi. Urine is a sterile, acid fluid. It flushes the ureters, bladder and urethra and helps prevent the growth of microorganisms.

Question 41

Tregs

Answer 41

These T cells play a role in regulating or suppressing other immune cells.

Question 42

Natural active immunity

Answer 42

Immunity that results from natural exposure to a pathogen.

Question 43

Artificial active immunity

Answer 43

Immunity that results from the deliberate introduction of weakened or disabled pathogens into the body

Question 44

Attenuated pathogen

Answer 44

Pathogens that have had their disease-causing ability removed and/or are not able to replicate in human cells

Question 45

Indirect Transmission

Answer 45

When the spread of disease through an intermediate vehicle. This means the disease may be transmitted by animal or insect vectors through the air, food or water, or by inanimate objects. Examples include: Food borne transmission, waterborne transmission, airborne transmission, vector borne transmission and contaminated objects

Question 46

Direct transmission

Answer 46

When a disease is spread from person to person whether it’s through skin to skin contact, droplets or fluids.

Question 47

Physical Barriers - Respiratory tract - Nasal Cavity

Answer 47

The hairs and mucus within the nasal cavity traps pathogens and can trigger the body’s reaction to sneeze. Coughing and Sneezing- both actions are a result of the cilia being agitated and are human reactions to expel any foreign particles or agents